Original subtitles

The southern drylands of Africa

are some of the most arid and treacherous on earth.

Places of wind whipped sand dunes

and slowly crumbling mountains.

Where the scars of dead rivers remain,

Closely guarded by the sun.

Here some remarkable desert specialists

have adapted to exist almost without water.

Theirs are the secrets to survival in this hostile realm -

This is the story of southern Africa's Greatest Drylands.

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In the sandy interior of south west Africa's Namib desert,

two elephant bulls are on the move.

They're searching for water.

In a place like this,

their quest is long and by no means guaranteed.

For the Namib has almost no surface water.

The elephants have little choice but to continue their trek.

Only those animals and plants

specifically adapted to desert life can live here.

They each know the secret of this place.

Although invisible for the most part,

moisture has never completely abandoned the Namib.

The key to living here

is learning how to find it.

For these ultimate desert wanderers, the search continues.

Namibia contains some of the most arid environments on earth.

Much of which receives less than 1 inch of annual rain.

These are the southern drylands.

Remote and barren landscapes of desolate beauty.

There are giants here

that dwarf even the mighty elephants.

These wind-whipped hulks

are some of the largest sand dunes in the world.

They dominate the coastline of the Atlantic ocean.

And extend inland into a sea of sand

as beautiful as it is hazardous.

This is one of the driest places in Africa.

Where rain is practically non-existent.

Yet there is life here.

Its support system is carried in from the sea.

Arriving as life-bringing fog.

As the cold ocean cools the prevalent south westerly wind

it creates fog, which blows in towards the land.

Here it spreads a vital but fleeting layer of moisture

up to 37 miles inland -

allowing life to take a precarious but lasting hold

on the sandy landscape.

Even with this minute daily veil of moisture,

those that live here have to be exceptionally good

at solving the problems of living in a super-heated land.

The Namib sand gecko's huge eyes

and pale, almost translucent skin

make it appear poorly equipped for the rigors of desert life.

It has a simple solution to staying cool in the heat -

it hides from the sun,

sleeping under the sand by day

where temperatures are less extreme.

This gecko spent the night hunting insects.

But now as the desert warms in the morning sun,

it will soon be forced to retire underground.

But before that

it needs to clean its bulbous eyes.

Which are getting blasted by sand.

They're its main tools for finding food in the dark

and it's of paramount importance

that they are kept in good working order.

Using a sticky, dexterous tongue

the gecko gently wipes any excess grime

off its sensitive eye balls.

Now it's time to find a subterranean hideout

to avoid the heat of the day.

But it's picky about real estate

and will only occupy compacted windward facing dunes.

Where hard crusts of sand

make for a solid roof over its head.

Living on the ground

means the Namib sand gecko doesn't need the sticky toes

common to most tree dwelling geckos.

It has swopped adhesive ability

for another much more useful adaptation.

It has shovels for feet.

Webbed toes are a rare specialization

which help it move loose sand quickly.

The gecko will emerge again to hunt

only in the cover of darkness.

There is another reptile in the southern drylands

that has a different solution

to life under the baking sun.

Undoubtedly one of the desert's most unusual inhabitants

is the Namaqua chameleon.

Chameleons are often found in lush tropical forests

and like her cousins,

this female Namaqua chameleon

has eyes that can swivel independently.

She's also cold-blooded

and cannot control her body temperature internally.

So how does the chameleon manage to regulate body heat

in a desert where the temperature can quickly jump

from 60 to 140 degrees Fahrenheit?

The secret is in her skin.

It contains pigments and crystals,

which the chameleon can control to vary her color.

In the cold mornings

when temperatures in the desert are still low

the Namaqua chameleon turns her skin a dark brown,

increasing the amount of heat she can absorb.

Soon she reaches the upper limit

of her preferred body temperature,

which is about 100 degrees Fahrenheit.

Now she's at risk of overheating.

But the highly adaptive chameleon has a solution.

She changes her color again,

this time to a lighter hue,

which increases the amount of light reflected off her skin,

so it will absorb less heat.

She also flattens her body and points herself towards the sun,

reducing the surface area directly exposed

to the warming rays.

These incredible adaptations

allow the chameleon to keep her body temperature

in a comfortable range

and remain active all day.

Though active is a relative term for her relaxed pace.

But what exactly does the chameleon eat out here?

The answer lies in the green patches of life

dotting the sand.

Few plants are more valuable to the desert's inhabitants

than the Narra plant.

It provides both food and shelter for many animals,

large and small.

Flower buds house a host of insects,

like these tiny aphids.

This larger bug prefers the ground level for its needs.

The plana beetle is a pedestrian insect,

meaning it can't fly.

Right now these three don't need to.

They are in a hurry. But it's not a race to food

that's got these beetles running.

This chase is actually a rather complicated lover's triangle.

The beetle in front is a female,

the two behind are eager males.

Male plana beetles

are single-minded in their quest to reproduce

and will attempt to mate whenever they meet females.

But finding the opposite sex is the easy part.

It's shaking the competition that takes hard work.

Having such persistent suitors is tiring

and she stops between sprints.

One way of dealing with your problems

is burying your head in sand.

But this doesn't deter her armored knights.

The moment is ruined by the lack of common courtesy.

And the chase resumes.

In a moment of confusion

the trio splits,

giving the leading male another chance.

In the race to mate, male plana beetles

need speed and size to come out on top.

Luckily they are the fastest running beetles in the world.

Again the female buries herself.

This is actually her way of taking shelter for the night.

But it serves the dual purpose

of allowing the male to mate with her

and stay above her to guard her against rivals.

The plana beetle isn't the only dryland expert

that relies on the Narra fruit for sustenance.

By eating moisture-rich melons

the handsome oryx

can go for long periods of time without drinking,

allowing it to venture deep into the driest interior.

But this special antelope has an even more impressive adaptation

that lets it stay out in the heat all day long.

In the sun its body temperature rises slowly but steadily,

reaching a brutally hot 110 degrees Fahrenheit.

If blood at this temperature reaches its brain

it would be fatal.

But the oryx has an ingenious 'blood flow radiator'

located in its nose .

This circulates and cools the blood

before it reaches the brain.

This system of cooling is crucial to the oryx

as it saves vast amounts of water

that would otherwise be used in staying cool through sweating.

This allows it to stay deep in the heat haze for days.

Herbivores like the oryx inevitably provide waste,

which enables the presence of an industrious dryland inhabitant.

The Flightless dung beetle is a hard worker,

committed to the tireless recycling of animal waste.

But today it's looking for a decent place to dig a hole

and escape from the heat.

Dung beetles are superbly designed for digging,

with a broad bulldozer-like head

and strong flat forelegs.

But the sand here is loose and difficult to dig.

Most dung beetles would simply fly away

to a more promising location.

But for this species that's not an option.

It's one of the few dung beetles that cannot fly.

In a remarkable evolutionary trade-off

it has given up the luxury of flight

for the necessity of retaining water.

Breathing out carbon dioxide uses up precious moisture.

Instead the beetle stores the carbon dioxide

in tiny tanks where its inner wings once were.

This reduces its need to breathe

and means it only has to 'exhale'

once every half hour.

In one of the driest places in the world

being able to conserve every bit of moisture

is the difference between surviving and perishing.

But it still doesn't help the beetle

find a decent place to dig a hole.

Along the coastal dune belt of the southern drylands,

fog provides enough moisture to support the entire ecosystem.

In the mountainous northern interior

an altogether different water source

provides for a more impressive cast of animals.

A dry river bed is all that's left

of the body of water that once carved its path

through these mountains.

Its history is now etched into the desert's sandy surface.

In times of flood the river may flow briefly

before the thirsty sand drags all the moisture underground.

But for now, the water is only accessible

to plants and trees with long roots,

which can tap the hidden reserves deep in the sand.

This vegetation sustains a variety of wildlife.

Including the largest land mammal on earth.

These are desert-adapted elephants

that have travelled long distances

to this remote river course

in search of water.

This is one of the last herds of desert elephants

left in southern Africa.

They are a family of related females and their young

led by the matriarch.

Who is the oldest and most experienced among them.

The matriarch has been here before

and knows that there is enough food for her family

and somewhere, hidden in the baking sand,

water.

Her challenge is to remember where it is.

The bulls travel separately from the herd

and are still far out in the immense desert.

The water source that they're searching for

flows invisible beneath the sand for thousands of miles.

While it supports plants and animals above ground,

it holds strange secrets below.

Where there is water life always follows.

This underground cave is home to the drylands' rarest creature.

The Golden catfish.

A species so rare

that it has been found nowhere else in the world.

Only a handful of individuals live in this small pool,

making the Golden catfish critically endangered.

Its long, eel like body

is an eerie pinky-gold due to a lack of pigmentation.

The bizarre little fish is totally blind.

Sight is superfluous when you live in the dark.

The Golden catfish have existed in this small water-filled cave

for generations.

So the real question here is -

what does it eat?

The answer comes from above:

Bat droppings.

High in the crevices above,

bats cling to the crags.

Their excrement falls into the pool

where the catfish can find it -

using their four pairs of thread-like barbels.

The bats thus provide the ghostly fish with a ready meal.

The southern drylands are full of mystery.

There are even occurrences that science can't fully account for.

These round circles of grass are part of a bizarre phenomenon

that remains unexplained.

Fairy circles.

Most scientists suppose that the fairies who make them

may in fact be termites.

The insects are believed to create the rings

by excreting a chemical that stops the growth of the grass

in the center of the circles.

But this explanation hasn't been verified

and other theories include burrowing animals,

electromagnetic waves

and even grand speculations

like UFO landing sites.

Still the fairy circles remain a great mystery

of southern Africa's drylands.

Grass like that of the fairy circles

is incredibly resilient

and is considered one of the perennials of the desert biome.

Along the coastal dunes little else can grow,

yet it tenaciously clings to the sand.

It appears at first glance

dry and dead.

Indeed for the most part it is,

until rare and precious rain falls to reawaken it.

Even in a state of suspended animation

the grass provides a home for another dune species.

The Dune ant is a dangerous creature,

not to be trifled with.

Living in large colonies,

individuals are equipped with formic acid and powerful jaws,

which they use to quickly dismember any unwary traveler

who comes into their territory.

Each ant has a clearly defined role.

Communication is the key to smooth operating.

This is done through exchanging chemical signals

called pheromones.

These workers in charge of burrow maintenance

are receiving an alarming message.

Winds have wrought havoc on the entrance of their home

beneath the grasses.

Clumps of sand and twigs are strewn everywhere.

To the tiny insects,

this is the equivalent of an earthquake

or land slide.

Luckily as a species,

ants have what would seem to humans like super strength.

Some estimates suggest

that ants can lift up to 50 times their own weight.

But will this be enough to clear what compared to the ants

look like massive fallen trees?

They need to work fast,

because without the entrance clear

the safety of the colony is compromised.

It's a Herculean task,

but finally their burrow entrance is clear enough

that they can continue with their day.

For these tireless ants,

life in the more extreme parts of the southern drylands

is made possible by the hardy grass.

For the elephants,

one of their lifelines in the desert interior

also comes in the form of a very special plant.

The Faiderbia Albida, or Ana tree

is a beacon of support for many in the driest times of the year.

Its long roots push down as far as 260 feet

to reach deep groundwater,

allowing them to grow big

and produce nutritious green leaves and seed pods.

This happens in August,

late winter in the southern drylands

and a time when most trees are dormant.

It's now that the Ana tree

drops its large, nutrient dense seed pods.

The seeds are one of the reasons the elephants have made

the long journey to the area from the desert interior.

For them even the exposed root of an Ana tree

can become a potential meal.

But getting it out of the ground

is harder than it would first appear,

even for Africa's most powerful mammal.

Try as she might, she can't get a good grip on the tough root.

Finally she gives up in a flush of frustration.

The trees also throw wide covers of shade,

a valuable resource for the elephants.

They move between the trees,

picking up seed pods with their dexterous trunks.

Together the herd travels vast distances

across the southern drylands in search of water.

Their survival is made possible

by scarce oases of life in an otherwise barren desert.

There is another animal here that has a more obvious impact

on the Ana tree.

Their rounded canopies are trimmed from below,

cut straight as if by the sheers of a giant gardener.

Indeed there is only one animal tall enough for the job.

Standing at 18 feet when fully grown,

the giraffe browses the lowest reaches of the trees.

It uses its long prehensile tongue

to grab and pluck the leaves.

But even the tallest land mammal in the world

sometimes comes up short.

And although a little awkward,

the giraffe won't turn its nose up at the tasty seed pods

that have fallen to the ground.

Giraffes generally maintain casual associations,

unlike the more socially cohesive elephants.

This herd is made up of mostly females,

with one dominant bull among them.

Giraffes spend roughly half their day feeding,

with females taking longer to select more nutritious foliage.

Between bulls dominance is decided by seniority and size.

Making this match up

rather uneven.

It's more like play fighting

with a younger brother for the large bull.

Who's clearly pulling his punches.

Giraffes are superb desert dwellers,

getting all the moisture they need from their food.

But the elephants must drink

and will need to find water soon or face the risk of dehydration.

Luckily the morning dawns with a gift from the heavens.

Low in the sky hangs fog

that has crept inland from the ocean.

It's the very same life-giving fog

that supports the dune seas along the coast.

As the sun rises the fog slowly burns off,

but not before being caught by a very clever tree.

It looks out of place with its verdant, pine like shape,

but the Tamarisk tree is an accomplished desert survivor.

The Tamarisk uses a special trick to catch the fog.

By producing a layer of salt on its leaves overnight

the tree attracts moisture,

which keeps it cool and well-watered.

Its high moisture and mineral content

make it a favorite of the elephants.

But it's not going to be enough

to keep them going for long in this heat.

As the day progresses temperatures rise sharply.

For the younger elephants the heat is exhausting.

The adults cannot lie down

without risk of crushing their internal organs.

Rather they take dust baths,

which help protect their skin from the sun

and biting parasites.

Driven on by thirst, they must keep moving.

Desert elephants are the same species as those

found throughout Africa -

Loxodonta Africana.

But these have become desert adapted over time,

with only slight changes

in their features and characteristics.

Their legs are slightly longer in proportion to their bodies,

with wider foot pads,

better suited for walking on the soft sand.

They're also said to be able to go for longer periods

without water than savanna elephants.

Even so, it's been several days since they drank

and they are parched.

The matriarch has led them out into the open.

But she has done so with good reason.

Here, finally they've found water at a spring

that wells up from the depths.

The herd drinks deeply now,

with adults able to gulp down as much as 40 gallons at a time.

Then in the distance

figures emerge.

The bulls have arrived.

The herd welcomes the two biggest of their kind

with a tenderness characteristic of these noble giants.

These bulls are no doubt father and brother to many of the herd.

The coming together of the family

is a rare and special happening.

With the usually solitary bulls arriving to drink as if on cue.

Once the elephants have quenched their collective thirst

they walk off together,

disappearing slowly in to the desert.

Their journey is a never ending march,

as constant as the movement of the sun across the sky

in this great desert.

These drylands of southern Africa have been wrought by time

into magnificent landscapes of sand and stone.

They may be stark and perilous,

but are filled with wild wonder.

Across their reaches

examples of nature's most startling ingenuity abound.

These characters have evolved to be hardy and desert-adapted.

And thus exist with consummate skill where others would perish.

For only a special few

can make a home in the most extreme of places:

The Southern Drylands.

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